According to IMBWR.org
Ohmigod, I'm not getting any mail!
Every once in a while, you'll wake up and log on or go into work, get a cup of coffee and settle down for your daily fix of BMW trivia. Only your mailbox will be empty.
Try not to take this personally. Everyone else isn't really off somewhere talking about you.
What probably happened is that one of the many computers and network links between your computer and the IBMWR server went down. When this happens, mail addressed to you is returned (bounces back) to the server. After the server receives several bounces from your address, it reaches the conlusion that something is wrong with the route to your address. So you're unsubscribed. This prevents stacks of messages from being sent back and forth over the net until the problem resolves itself.
To fix the problem, you need to subscribe again. You cannot subscribe to the list twice, so don't worry about it. The worst thing that will happen is that you'll receive an error message from the IBMWR server, telling you that you're already a member of the list. If this happens, it means your mail is disappearing into the great bit bucket in the sky. Which means that it's a problem for you and your system administrator to resolve.
If this trouble shooting technique doesn't work, send an email message with your tale of woe to:
ibmwr@ibmwr.org.